Shell变量传递

#!/bin/bash

# echo father pid
echo "Father Process ID is $$"

# define local env
localvar="Define a local variable."
echo "localvar=$localvar"

ENVVAR="Define a environment variable."
export ENVVAR
echo "ENVVAR=$ENVVAR"

$PWD/child.sh

echo "Retrun to father process: $$"
echo "localvar=$localvar"
echo "ENVVAR=$ENVVAR"

#!/bin/bash

echo "Child Process ID is $$"
echo "My Father Process ID is $PPID"

echo "localvar=$localvar"
echo "ENVVAR=$ENVVAR"

localvar="Redefine this local variable."
ENVVAR="Redefine this environment variable."

echo "localvar=$localvar"
echo "ENVVAR=$ENVVAR"